Chris Lattner | 10e286a | 2010-11-23 19:19:34 +0000 | [diff] [blame^] | 1 | //===--- FileSystemStatCache.cpp - Caching for 'stat' calls ---------------===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file defines the FileSystemStatCache interface. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include "clang/Basic/FileSystemStatCache.h" |
| 15 | #include "llvm/System/Path.h" |
| 16 | using namespace clang; |
| 17 | |
| 18 | MemorizeStatCalls::LookupResult |
| 19 | MemorizeStatCalls::getStat(const char *Path, struct stat &StatBuf) { |
| 20 | LookupResult Result = statChained(Path, StatBuf); |
| 21 | |
| 22 | // If the chained cache didn't know anything about the file, do the stat now |
| 23 | // so we can record the result. |
| 24 | if (Result == CacheMiss) |
| 25 | Result = ::stat(Path, &StatBuf) ? CacheHitMissing : CacheHitExists; |
| 26 | |
| 27 | |
| 28 | // Do not cache failed stats, it is easy to construct common inconsistent |
| 29 | // situations if we do, and they are not important for PCH performance (which |
| 30 | // currently only needs the stats to construct the initial FileManager |
| 31 | // entries). |
| 32 | if (Result == CacheHitMissing) |
| 33 | return Result; |
| 34 | |
| 35 | // Cache file 'stat' results and directories with absolutely paths. |
| 36 | if (!S_ISDIR(StatBuf.st_mode) || llvm::sys::Path(Path).isAbsolute()) |
| 37 | StatCalls[Path] = StatResult(Result, StatBuf); |
| 38 | |
| 39 | return Result; |
| 40 | } |